NYC-WTC_000232104

NYC 9/11 Public Portal Document

EMSL Analytical, Inc. 107 Haddon Ave., Westmont, NJ OSlOg

EMSL Order 10:040305286 Attn: Andrew/ M N. Khan Customer ID: JLCC50 JLC Environmental Consultants, Inc. Customer PO: 200 Park Ave South, Suite 1001 Date Received; ’ 04/05/03 12:23 AM NewYork, NY 10003 Fax: 212-420-6092 EMSL Order: 040305286 Project; #03-2744/NYCDEP—114 Liberty ST EMSL Project ID: Report Date: 04/14/03 Date Analyzed: 04/14/03

Silica, Crystalline Analysis Performed X-Ray Diffraction (XRD) Modified MOSH Method 7500, Issue 3,1/15/98

I Respirable Dust Airborne Silica Sample Sample Silica Silica % Analytical Sample ID Identification Particle Volume Weight Cone, Weight Cone. Silica Sensitivity ID (L) (<ng) (mg/m’) (mg) (mg/m’) (mg/m’)

MB13687-1 12THFLR SOUTH Quartz 408 <0.002 N/A <0.0045 <0.0110 N/A 0.0110 MB 13687-2 1ITH FLR DINING Quartz 408 <0.002 N/A 0.0090 0.0221 N/A 0,0110 MB13687-3 lOTH FLR DINING Quartz 408 0.601 1.4730 0.0080 0.0196 1.3 0,0110 MB13687-4 9TH FLR DINING Quartz 408 0.014 0.0343 0.0090 0.0221 64.3 0.0110 MD13697-5 8TII FLR DINING Quuilz. 408 <0.002 N/A <0.0045 <0.0110 N/A 0.0110 MB13687-6 7TH FLR DINING Quartz 408 0.010 0.0245 <0,0045 <0.0110 45.0 0.0110 MB13687-7 6TH FLR DINING Quartz 408 0.090 0.2206 <0.0045 <0.0110 5.0 0.0110 MB136g7.g STH FLR DINING Quarte 408 <0.002 N/A <0.0045 <0.0110 N/A 0,0110 4TH FLR MB13687-9 KITCHEN Quartz 408 0.115 0.2819 <0.0045 <0.0110 3.9 0,0110

Disclaimer: The laboratory can only verily the concentration of silica on the filter and not the final concentration due to data obtained by non-laboratory personnel. In the absence of a bulk dust sample, neither the specific forms of crystalline silica nor the interfering species can be fully determined. Hence, the amount for each phase, if anticipated, will be analyzed based on primary, secondary, and/or tenlary peak data with comparison to calibration curves ot known standards. It should be noted that air samples are meant for only quantifying silica (or a mineral phase) which must first be identified from a bulk dust sample. “<” means less than the stated value. The lowest reportable value is equivalent to the Analytical Sensitivity that is calculated from the lowest reprnducihle amniint of specific mineral detectable by the instrument.

Anant Samndra, Ph.D, Analyst Stephen Siegel, CIH-Iiab Manager Or other approved signatory

AIHA Accredited - Laboratory ID 11100194 Pagel of 3

CITY_DEP_WORBY_CANNATA_SUBP_000085293

NYC-WTC_000232104